THE SNP is investigating recent complaints of sexually inappropriate behaviour against some of its most senior politicians.

The party said two individuals had complained about different parliamentarians, but would not say which parliaments were involved.

The SNP has 60 male parliamentarians - 36 MSPs, 22 MPs and two MEPs.

The admission came as Holyrood and Westminster both promised a “zero tolerance” approach to sexual harassment by MSPs and MPs.

Holyrood party leaders are due to hold an urgent meeting tomorrow to discuss the problem.

The action follows claims that sexual harassment by MSPs is “rife” at Holyrood.

Human-rights lawyer Aamer Anwar said women ranging from MSPs to interns had complained of sexual abuse or harassment in the Scottish Parliament, and accused politicians of maintaining an “abject silence” on the issue.

Rosa Zambonini, a former SNP councillor in North Lanarkshire who now works for SNP MSP James Dornan, said she had been harassed in both Holyrood and the council.

Writing on her Just Rosa blog, she blamed “lecherous men” but did not identify them.

She wrote: “Have I been harassed in the Scottish Parliament? Yes.

“Have I been harassed at NLC [North Lanarkshire Council]? Absolutely.”

Former Labour leader Kezia Dugdale said there was a “clear” problem at Holyrood, with female MSPs subjected to sexual behaviour, language and gestures from male MSPs.

Nicola Sturgeon said the SNP was bracing itself for further complaints.

The First Minister, who has proposed a cross-party review of Holyrood procedures to deal with the problem, said the parliament should confront any allegations "head-on".

She said: “This is a line-in-the-sand moment where all of us can say, firstly and foremostly, to men that indulge in this kind of behaviour, that it's not acceptable.

“[And] as organisations - whether that's parliament, parties or workplaces - that we will act and have a zero-tolerance approach to any kind of behaviour like this."

She said: “I fully expect that we will have concerns coming forward, like every political party will, and we will investigate them, if they come forward, in an appropriate way.

“I don't think any party can assume it's immune from behaviour like this.

“What I'm determined about is that if there are any issues raised associated with the SNP, they will be properly and rigorously investigated.”

She said she was confident the SNP internal procedures were working, but added they would be looked at “critically” to see if they could be improved.

SNP insiders said it was often unclear to whom staff should complain, and people were afraid in case they were not believed and their careers ruined.

An SNP spokesperson said: “The SNP has had concerns of this nature raised by two different individuals. The individuals and their concerns are unconnected to each other.

“These will be fully investigated but enquiries remain at an early stage.

“We will do nothing to deter people from coming forward and, as such, we will not comment further while investigations are ongoing.”

After weekend reports that Tory whips were protecting sex pest MPs, Commons Speaker John Bercow called on all parties to “live up to their responsibilities” and take action.

“Make no mistake, there is a need for change," he said.

Earlier, Ms Sturgeon proposed a cross-party review of Holyrood procedures to deal with any problem, and said the parliament should be prepared to confront any allegations "head-on".

She said she was not aware of any allegations against SNP MSPs or MPs but added: “I fully expect that we will have concerns coming forward, like every political party will, and we will investigate them, if they come forward, in an appropriate way.

“I don't think any party can assume it's immune from behaviour like this.

“We want to think we are, but what I'm determined about is that if there are any issues raised associated with the SNP, they will be properly and rigorously investigated.

"I have confidence in the procedures we have got in place but I've also decided we are going to look critically at those procedures to see if there are further steps that we need to take to give women the confidence that if they have concerns or complaints they can bring those forward.

"This is a line-in-the-sand moment where all of us can say, firstly and foremostly, to men that indulge in this kind of behaviour, that it's not acceptable but as organisations - whether that's parliament, parties or workplaces - that we will act and have a zero-tolerance approach to any kind of behaviour like this."